Beginner Exercise 21 / Solution

White escapes!  

Black is caught in a connect-and-die. If Black a, White b captures. Otherwise, White captures at a (or b snapback), and is connected to the outside and escapes, thus living (by tsumego convention).

White failure  

The double atari is wrong. Black chooses to keep the marked cutting stones, preventing White's escape. After captures, Black reduces the first line to no eyes with two hanes: and .

Variation  

If White makes an eye on the first line, captures and White only gets one eye.